Process of insulating electrical conductors.



TTNTTED STATES PATENT @TFTQTJ.

GEORGE H. RUPLEY, F SOHENEOTADY, NEW YORK, AssrGNOn 'rO GEN RRAL- ELECTRIC COMPANY, A. OORPOaArION OF NEW YORK.

No, eeasav.

Specification ofLetters Patent.

Patented Nov. 6, 1906.

Application filed January 13, 1906. Serial No. 295,868.

To aZZ whom it may concern: 4

Be it known that LGE R E RUPLEY', a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have in'vented certain new and useful Improvements the Process-of Insulating Electrical Conductors, of which the following is a specification.

- This invention relates to the insulation of metal employed in, electrical appliances, and finds special application in insulating wire, but is also used in other connections-such, for instance, as coating the core laminations of transformers. The rocess forms on the surface of the-wire or o't er conductor a thin tough elastic firmly-adherent film which is waterproof, hashigh dielectric pro erties, is infusible at all temperatures to W ich it is exposed in service, is not inflammable, does not flow under pressure, and does not crackor scale off when the wire is bent even on a curve ofsmall radius. Moreover, it is so thin as to enable a given length of wire to be coiled in considerable less space than is possible with cotton or silk covered wire.-

This invention constitutes an improve ment on that set forth in my previous patent,

.No. 806,574, granted December 5, 1905.

The process therein disclosed is entirely successful inpractice; but it has been found that by modifying my process as hereinafter set forthan insulation is obtained which is more zinc and a substantially similar quantity ofoxid of lead. The mixed massis then raised to a temperature of from 550 to 600. Eahr'enheit and the heat continued until theoxidfisentirely taken u bythe oil and thmq rred degree of distillation efiected during which the glycerids are broken up and glycerin set free. When'the mass acquires a good degree of stiffness, about twenty-five per cent. of a rocess as heretofore carried on and and the mass allowed to cool. The film is then hardened by the application of heat, and the arrangement whereby it is accomplished is fully 'set forth in the above-mentioned patent. The result of this process is a smooth, black, and glossy coating of a residuum of the oil. It has been found, however, that for certain uses it is'preferable to have an insulation which does not have a gloss or polish, but which will have a dull finish slightly roughened, so that there will be more friction between the turns. This is found particularly desirable in certain kinds of Winding-Tris, for instance, in the case of universal Winding, where it is essential that there be more surface friction than in other methods of winding. For these reasons and also to give body to the insulation and to form a mechanical se arator I add a certain amount-say from ve to ten per cent.of some solid material, such aschinaclay or lump clay. 'Other poW-,

of the solvent. It is possible by this process to obtain a thicker insulation with -a less number of applications Which in someinstances is desirable, especially in the case-of plates or large wire, Where considerable pressure may be applied to the conductor. The dull finish given to the Wire also has advantages which will be evident to those skilled in the art. The inert filler is also of special ad-, vantage where great pressure is used, as it acts as a resisting spacer.

While I have described my invention as consisting of certain steps inthe process and in the use of certain materials, it should be understood that I do not limit my invention .to "the particular materials or process steps except as it is limited by the scope of the claims annexed hereto.

, What I claim as new, and desire to secure by-Letters Patent of the United States, is- 1. The process of insulating an electrical conductor which-consists in substantially refractory solvent, such as rosin-oil, is added I freeing'an oil-fromthe glycerin of cornbina tion mixing a powdered "material with the resultant product, applying a film of the mixture to the conductor, and hardening the film by heat. a I

2. The process of insulating an electrical conductor which consists in substantially freeing linseed-oil from the glycerin of combination mixing a powdered material with the resultant product, applyin a film of the mixture to the conductor, and Tiardening the film by heat.

3. The process of insulatin an electrical conductor consisting in dissoTving a previously-thickened and partially-decomposed oil in a suitable solvent, mixing a quantity of solid matter with the solution, applying a film of the solution to the conductor, and hardening the film by heat.

4. The process of insulating an electrical conductor consisting in mixing a quantity of powdered material with a vegetable oil substantially free from glycerin, applying a film of the compound to the conductor, and hardening the film by heat.

5. The process of insulating an electrical conductor which consists in setting free the glycerin and fatty acids in a quantity of linseed-oil, driving off the glycerin, mixing a quantity of granular material with the fatty acids, applying a film of the mixture to the conductor, and then hardening the film'by heat- 6. The process of insulating an electrical conductor consisting in substantially freeing a quantity of vegetable oil from glycerin,

mixing a heat-refractory powder with the resulting product, applying a film of the mixture tothe conductor, and then hardening the coating by heat.

7. The'process of insulating an electrical conductor consisting in mixing one or more metallic oxids with a vegetable oil, boiling residuum in a suitable solvent, mixing a quantity of silicate with the solution, apply metallic oxids with linseed-oil, maintaining the mixture at atemperature above 5OQ Fahrenheit until it becomes stiff and elastic '4 the mixture to break up the glycerids and I free and drive off the glycerindissolvingqthe,

at ordinary temperatures, dissolvingthe stifiened mass 111 a refractory solvent, mlx n'g a quantity of clay with the solution, and hardening the coating by heat. 1, I J

I In witness whereof I have hereunto set my hand this 1 1th day of January, I906.

GEORGE H. RUPLEY.

Witnesses: I

BENJAMIN B. HULL, HELEN ORFORD. 7 

